An OPC UA PubSub Implementation Approach for Memory-Constrained Sensor Devices

Open Platform Communications Unified Architecture (OPC UA) comprises 14 specifications to deploy an industrial system with reliability, security, and interoperability. While realizing this standard, the devices of the considering industrial system must have enough capabilities in computation and storage. It is a challenge in the Industrial Internet of Things (IIoT), a scenario in which field-level devices can be memory-constrained sensor devices. Tailoring OPC UA to fit such devices requires advanced programming skills; otherwise, system developers must simplify or remove some essential features of OPC UA. This paper presents another implementation approach to tailor OPC UA PubSub, a specification for the publish-subscribe messaging pattern, into memory-constrained sensor devices. This approach, titled OPC UA PubSub-C, proposes using a remote OPC UA server as a configurator to operate large-memory-footprint tasks for field-level devices.